Field of the Invention
This invention relates to a process for manufacturing a petroleum resin, and, more particularly, to a process for manufacturing a light-colored petroleum resin with a high commercial value by remarkably improved operations. The process comprises polymerizing a petroleum fraction of a 10.degree.-280.degree. C. b.p. range containing unsaturated hydrocarbons and produced by thermal cracking of naphtha or the like or by petroleum refining process, or a mixture of such a petroleum fraction and industrially available styrene monomer derivatives, in the presence of a Friedel-Crafts catalyst, and efficiently removing the catalyst residue or ash.